Le 13/07/24 - 11:35, Maíra Canal a écrit :
> On 5/16/24 10:04, Louis Chauvet wrote:
> > Add some documentation on pixel conversion functions.
> > Update of outdated comments for pixel_write functions.
> >
> > Signed-off-by: Louis Chauvet <louis.chauvet@xxxxxxxxxxx>
> > Acked-by: Pekka Paalanen <pekka.paalanen@xxxxxxxxxxxxx>
> > ---
> > drivers/gpu/drm/vkms/vkms_composer.c | 7 ++++
> > drivers/gpu/drm/vkms/vkms_drv.h | 15 ++++++++-
> > drivers/gpu/drm/vkms/vkms_formats.c | 62 ++++++++++++++++++++++++++++++------
> > 3 files changed, 74 insertions(+), 10 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/vkms/vkms_composer.c b/drivers/gpu/drm/vkms/vkms_composer.c
> > index c6d9b4a65809..da0651a94c9b 100644
> > --- a/drivers/gpu/drm/vkms/vkms_composer.c
> > +++ b/drivers/gpu/drm/vkms/vkms_composer.c
> > @@ -189,6 +189,13 @@ static void blend(struct vkms_writeback_job *wb,
> >
> > size_t crtc_y_limit = crtc_state->base.crtc->mode.vdisplay;
> >
> > + /*
> > + * The planes are composed line-by-line to avoid heavy memory usage. It is a necessary
> > + * complexity to avoid poor blending performance.
> > + *
> > + * The function vkms_compose_row is used to read a line, pixel-by-pixel, into the staging
>
> Nit: I know it's not kerneldoc, but I'd be glad if you use
> vkms_compose_row()
>
> > + * buffer.
> > + */
> > for (size_t y = 0; y < crtc_y_limit; y++) {
> > fill_background(&background_color, output_buffer);
> >
> > diff --git a/drivers/gpu/drm/vkms/vkms_drv.h b/drivers/gpu/drm/vkms/vkms_drv.h
> > index b4b357447292..212f4ab6a71f 100644
> > --- a/drivers/gpu/drm/vkms/vkms_drv.h
> > +++ b/drivers/gpu/drm/vkms/vkms_drv.h
> > @@ -25,6 +25,17 @@
> >
> > #define VKMS_LUT_SIZE 256
> >
> > +/**
> > + * struct vkms_frame_info - structure to store the state of a frame
>
> s/structure/Structure
>
> > + *
> > + * @fb: backing drm framebuffer
> > + * @src: source rectangle of this frame in the source framebuffer, stored in 16.16 fixed-point form
> > + * @dst: destination rectangle in the crtc buffer, stored in whole pixel units
> > + * @map: see drm_shadow_plane_state@data
> > + * @rotation: rotation applied to the source.
> > + *
> > + * @src and @dst should have the same size modulo the rotation.
> > + */
> > struct vkms_frame_info {
> > struct drm_framebuffer *fb;
> > struct drm_rect src, dst;
> > @@ -49,9 +60,11 @@ struct vkms_writeback_job {
> > };
> >
> > /**
> > - * vkms_plane_state - Driver specific plane state
> > + * struct vkms_plane_state - Driver specific plane state
> > * @base: base plane state
> > * @frame_info: data required for composing computation
> > + * @pixel_read: function to read a pixel in this plane. The creator of a vkms_plane_state must
>
> s/vkms_plane_state/struct vkms_plane_state
>
> > + * ensure that this pointer is valid
>
> Note: "If the @argument description has multiple lines, the continuation
> of the description should start at the same column as the previous
> line:" [1]
>
> [1] https://docs.kernel.org/doc-guide/kernel-doc.html#function-parameters
>
> > */
> > struct vkms_plane_state {
> > struct drm_shadow_plane_state base;
> > diff --git a/drivers/gpu/drm/vkms/vkms_formats.c b/drivers/gpu/drm/vkms/vkms_formats.c
> > index d597c48452ac..f157c43da4d6 100644
> > --- a/drivers/gpu/drm/vkms/vkms_formats.c
> > +++ b/drivers/gpu/drm/vkms/vkms_formats.c
> > @@ -9,6 +9,18 @@
> >
> > #include "vkms_formats.h"
> >
> > +/**
> > + * pixel_offset() - Get the offset of the pixel at coordinates x/y in the first plane
> > + *
> > + * @frame_info: Buffer metadata
> > + * @x: The x coordinate of the wanted pixel in the buffer
> > + * @y: The y coordinate of the wanted pixel in the buffer
> > + *
> > + * The caller must ensure that the framebuffer associated with this request uses a pixel format
> > + * where block_h == block_w == 1.
> > + * If this requirement is not fulfilled, the resulting offset can point to an other pixel or
> > + * outside of the buffer.
> > + */
> > static size_t pixel_offset(const struct vkms_frame_info *frame_info, int x, int y)
> > {
> > struct drm_framebuffer *fb = frame_info->fb;
> > @@ -16,18 +28,22 @@ static size_t pixel_offset(const struct vkms_frame_info *frame_info, int x, int
> > return fb->offsets[0] + (y * fb->pitches[0]) + (x * fb->format->cpp[0]);
> > }
> >
> > -/*
> > - * packed_pixels_addr - Get the pointer to pixel of a given pair of coordinates
> > +/**
> > + * packed_pixels_addr() - Get the pointer to the block containing the pixel at the given
> > + * coordinates
> > *
> > * @frame_info: Buffer metadata
> > - * @x: The x(width) coordinate of the 2D buffer
> > - * @y: The y(Heigth) coordinate of the 2D buffer
> > + * @x: The x (width) coordinate inside the plane
> > + * @y: The y (height) coordinate inside the plane
> > *
> > * Takes the information stored in the frame_info, a pair of coordinates, and
> > * returns the address of the first color channel.
> > * This function assumes the channels are packed together, i.e. a color channel
> > * comes immediately after another in the memory. And therefore, this function
> > * doesn't work for YUV with chroma subsampling (e.g. YUV420 and NV21).
> > + *
> > + * The caller must ensure that the framebuffer associated with this request uses a pixel format
> > + * where block_h == block_w == 1, otherwise the returned pointer can be outside the buffer.
> > */
> > static void *packed_pixels_addr(const struct vkms_frame_info *frame_info,
> > int x, int y)
> > @@ -52,6 +68,13 @@ static int get_x_position(const struct vkms_frame_info *frame_info, int limit, i
> > return x;
> > }
> >
> > +/*
> > + * The following functions take pixel data from the buffer and convert them to the format
> > + * ARGB16161616 in out_pixel.
>
> I believe it is @out_pixel.
Thanks for the review!
Yes it @out_pixel, I will fix those nits for the next iteration.
Thanks,
Louis Chauvet
> The content seems great to me, only those minor nits.
>
> Best Regards,
> - Maíra
>
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Louis Chauvet, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
